Telegraph system



Nov. 28, 1933.

R. v. MoRGENs'rERN Er AL 1,936,947

TELEGRAPH SYSTEM 4 sheets-sheet 1 Filed Oct. 5, 1931 y #fw mmm n e .wrmYM kwi, W0 wf? ....nia, cms. VH @wie d dan@ Wat @muuu NOV- 28, 1933- R.v. MORGENSTERN ET Al. ,1,936,947

TELEGRAPH SYSTEM Filed Oct. 5, 1931 4 Sheets-Sheet 2 NOV 28, 1933 R. v.MORGENSTERN Er AL 1,936,947 9 TELEGRAPH SYSTEM 4 Sheets-Sheet 4 PatentedNov. 28, 1933 tofThe- Western .Union Telegraph Company,

Y., a corporationv of New York Y Applicationfoetobe: `,v1931.s'riaw1N.567,104. :"z'clnms. (or17a-esl"4V j New York.; N.

signal Waverwhich 'is substantiallysquare-*topinl shape into a series ofvseparate'sharp peaksV v ofv current which mark the beginning` of theAindividual signal impulses of theorig'inal squaretop Wave, and totransmit these sharp peaks of current over the transmissionline. Itis a-further object of the invention to cenve'rt a 'received wave formcemprisingseparate sharp peaks of'current into 'a Wave substantiallysquare-top nshape and to utilize'the squaretop converted Wave foroperatingv receiving or repeatingapparatu'sff. ri Y "Other objectsr ofthe invention are to provide duplexed or superposed, or duplexedandsuperposed systems embodying lthe above mentioned features. s

` A related object of the invention is toelizninate ofsignalslat'incre'ased signaling speeds. Y

e l distortion and to' make possiblethe transmission '25 The inventionin an improved form makes use of thyratron' tubes 'for the reception andcon- Version Vof theseries cf sharp peaks of current into a wave formsubstantially square-topin shape; However, Within certainflimits itispossibleto practice the invention Withthe use of the ordinary polarrelay. f Y Figure 1a shows an embodiment of the methodOfsignaltransmission of thisinvention vin Ja simple circuit comprising atransmitting dis- 't'ributor and a'; receiving polar relayof ordinary,typen I, vt, y .l

Figure :flb' shows an alternative method vof receiving the signals bymeans of thyratron tubes.

Figure 2 shows thegeneral shape of thesignal vWave at `various stagesand'in various forms of the invention: Y

.. (a) vrepresents the 'Wave form inthe primary of the sendingtransformer.'

- y (b) represents the wave form in the' secondary' ofthe sendingtransformer`and` the line.

e 4. n. ai .c .v Y Y 'Y (c) represents thV received Wave iorm off theThe' secondary mnreuntw-u meppel@ serievsforf,

.Sharp fpeaksfon? .all @sist/ari? 0f; each '.Sgnalfand f contacts .ofthe receiving relay when a polar relay is used.'

(d) represents'the received Waveform inthe plate circuit when thyratrontubesare used in place of a polarrelay.v j V:Figures 3a, 3b andSC, whentaken together, shew a complete superposed group operating vover vtwosections -of line, usingimpulse'lsignaling,

AA being oneAsidevcircuitfBB' the other :slide lIt is tobenoted thatvarious"modificaLv tionsjof 'the' transmitting and of the receiving sapparatus'accrding to the'inventin' are `shown at' tom circuits.

Ronia'v. Morgenstern, nvingfon, and Jehu'` H, f ,Haekenbergg JacksonHeights, ,N. Y., assignors he several terni'vilr'ials!lof.-v they sideand phen? fr Thel fundamental' fpr'inciples.' underlying the operationof the system ofimpulse orindu'ce'd current telegraphy accordirig1A toinvention will be explained 'by'referericefto thesimple cirf` `euit'ofFig. 1a invvhich: 'lrepresentsal distribuof g a` sendingtransformer"13,;comprising' primary 4 and-secondary 5. The'prirnary 4-isgrounded at its second terminal-to-cemplete a'circuit eby 'Way ofth'eearth-y back to groundedtermina1f8 v 'of the current'scurceQ;connected to' distributor 1:V rV-he terminals of secondary 5jof`thejfsen'ding transformer are,l connected by vlinecendllctors 1 6,V'6i-to `the@Winding of -a receiving'polar relay-1,7, Operation `of vtheldistributor Will cause'la ovv of current in the fprima'ryiofthe-sending transformer 3, havingawave formlike'-that 'shownfin thefrequency is not/constant but that'the sig@ nal length varies"frontisignal to signal alsshown in the curves of Fig. 2:l The voltage-` ducedinte current and M is theniutu'alfinductance ofthe.

primary current is changing'avvoltage is induced lvtwovvindings."Inotherffvvordsgas long a'sthe in the secondary; but by the time theprimary LcurrentA hasreached .its -Vlsteadystate value, 4the sec'ondaryvoltage. will have risen to'V amaximum andV then 'fallen to lzeros.'n

Willhavefthe general lfor.rrr-shown in Figli', f.- -If .the,indi-letame. of; themrfimary s"kept10wv lmo n enough, so that 'theprimary currentyreaches its -steadystate value before reversa-loccursfor the fshortest signal, `then for all frequencies.' -lup ft'o.that determined' by this shortest sfignaLJthe" sec;-

ondary impulses will be alike, Vregardless of the.

sidual magnetism of the relay until the next im' pulse reaches it.Y Thearmature andfcontacts vthen may be made to recreate the signal impressedupon the primary of the sending trans-y former. Fig. 2c shows thesignals asV they Vwould,

appear off the contacts ofthe receiving relay. Vv

The short horizontal lines between impulses represent intervals inwhichl the'arm'ature of the polar relay is passing from one contacttothe other.

' -Ifvthere isV in the line induction of sufficient value to overcomethe residual magnetism of the relay, (as would be the case if one of thelines were replaced by a ground return or in-metallic circuits in somecases where an unbalance exists) then some arrangement, must bek madefor holding the armature on its contact until'the next impulse isreceived. This maybe done by any of several simple locking circuits, inthe manner which will be obvious to engineers. Y

l Fig. 1lJ illustrates amore satisfactoryreceiving y toY 1 shown inFig.v la.

arrangement and one which allows ofhigher signaling speeds than ispossible withrthe usual relay The receiving relay of Fig. 1a isreplacedby a receiving transformer 10, having its primary ll connected to theline conductors 6d, ,60ar J'Ihe-secondarylZ of the receiving transformer:is connected through vsuitable grid resistors 13 Yto the -grid cathodecircuits of a pair of grid-control rectiers or thyratron tubes 14.

As illustrated, the cathodes 15,15 of the thyratron tubesareconnected inparallel across a resistance 16, and, a conductor extends from the.electrical f mid-point ofresistance 16V-through batteryv 17 to ,coils20, 2 0, .andasource 21.of positive Ythe Velectrical. mid-point ofthesecondary` 12 Vof theV receivingl transformer .101VV `l-Iere thegridcathode circuits of the f tubes 14, 14 extend through the-two halvesofthe secondary 12 and lthe.,,respesti-ve Vgridresistors l13, 13 tothegrids 18, 18 of the thyratron tubes. The heating circuits, ofthecathodesare not shown.

The; plate circuits of Vthethyratrori tubes 14 extendv through'suitableplate'` resistors 19, y19, c l a Y Y j plate potentialrto the mid-pointof resistance 16. The

coils 20, 20 may be the windings ofA a relay, or'

the primaryof a sending Ytransformer for another section of line, or-thefields of a generator.

Thieadjustable condenser 22 is connected between the plates ofthe twothyratron tubes 14. v n

The wave shape of thecombined current in the two coils 20, 20 or thevoltage across them is represented in Fig'. Zdjl The operation of thesystemacco'rding to Fig.

1b is obvious. The original square-topwave from distributor 1, or someequivalent transmittingapparatus of wave form shown in Fig. 2?, having'been transformed intoa series of sharp `:pealfts of vcurrent having aWave formlike'thatf'shown in Fig. 2b', and transmitted over the line, isreceived in the transformer 10 and the impulses of `Valter,- natepolarity are applied to 'the` grids -of 'the thyratrons. Anincomingimpulse'of one polarity fis applied to thyratronsin such a directionVasfto render-.one of the thyratrons conducting,` While After it y.

l tube non-conductive, and vice versa. n

rbined effect of the alternate flow and cessation trons'isorepresentedin Fig. 2d.

,peaten vacuum tube amplifiers, as shown at-the beA substituted for theforms shown.

applied in such a direction as to render the second thyratronconducting. The circuits of the tubesV are arranged, in the usualmanner, so that the starting of the second tube causes a drop in theplate voltage of the first tube belowy the point at which conductivitycan loe-maintained, so that asuc'ceeding impulse of the oppositepolarity is the starting of the `second tube renders the firstv Y ofcurrent in the plate circuits of the two thyra- Itwill be apparenttherefore a system according to Fig. 1b, the signal ofwave formaccording to Fig. 2a is transformed by the sending transformer 3 into awave form like that shown in Fig. 2b and is received by the receivingtransformer 10 and thyrat'rons 14, 14 and converted into a wave formlike that shown in Fig. f 2d. Thus the original square-top wave isreconverted, after' transmission over the line, intoa square-top Wavehaving substantially the same form as the original Wave. y j YSimilarly, whenr using a system according to Fig. Vl?, a signal of waveform like that of Fig 2a is transformed by the sending transformer 3intoavwave form likethat of Fig. 2b and after transmission over the line `inthe form shownin Fig. 2b, isY received by the usual polar relay andconthat Iwhen using verted into air/ave form like that shownV in Fig.2c. 1,0 5

Disregarding the small gaps between impulses the wave of Fig. 2c issubstantially a duplicate of the original square-topvvave of Fig. 2a. Y

Inorder that the systemV may be,` duplexed and/ or superposed, it isnecessary to provide the 1.1;0

receiving transformer with four'equal primaries,

two to be usedin the line'and'two as-the artificial line coils. Thesecondary' ofthe sendingv transformer must be center-tapped toprovidegfor the phantom connection. Y f

In the Yduplexed and superposed system illustrated in Figs. 3a, 3b and3, AA represent the terminals of one side circuit, each comprisingtransmitting and receiving apparatus; BB represent the terminals ofthesecond side circuit each comprising transmitting and receiving appa-4ratus; CC represent the terminals of the phantom circuit veachcomprising. phantom transmitting and receiving apparatus;

At the terminals A and B different variations of thetransmittingapparatus according to this invention are shown. At the terminals, A, `Band C different variations of the receiving apparatus according to thisinventionv are shown.] Repeat- `ing apparatus isfillustrated for eachVof the side and phantom circuitsgThe` repeaters are allr shown alikealthough it may sometimes become necessary to incorporate, in thephantom reterminals of the phantom.,r Y

The distinguishing features shown in the various modifications oftransmitter arethat at the terminals VAA'both positive and negativebattery are used for transmissiomwhile at terminals BB only one pole ofbattery is used. At'the phan- 140 tom circuit terminals CC, as atterminals AA, both positive rand negative battery'arev used. But it isobvious that other forms of transmitter embodying the featuresof thisinventionA may The distinguishing features of the 'various modificationsof receiver are that vat therterminals AA a pair of thyratron tubes witha relay the plate circuits isshown as: the receiver,

While at `the terminals BB the standardl metallic circuit vline relay isusedat the terminal and the tubes omitted. The phantom circuit terminalsCC include'two more variations, namely, the

use of a threeLelement.thermionic vacuumxtube as an amplier 'of 'the'received impulsesbefore they. are impressed upon the'g-rids of thethyratronsfand the connection into'the plate circuits of the tubes oftheiields ofv afgeneratorand vthe associated shaping" apparatus. Thearmature of the generator may then be connected intoanother line sectionor into a local circuit.

The transmission at anyV terminal may be from a fork, a relay,acommutator crfrom a multiplex distributor. i f

Referring vnow in' detail tothe apparatus' in Figs. 3a, 3b and'SC: Theside circuit AAlcomprises two line sections including line conductors'30 and v31 respectively. The rst line section is balanced at its twolends vbysuitable artificial lines'32 and 33, in order to The receiv-"ing transformer by which tlielinel section 3Q is permit duplex operationthereover.

positive andY negative` battery, the armature of the transmitter being.permanently connected to the terminal of primaryi? and operating betweencontacts'connected to positive and negative battery as indicated.

The secondary 36 ofgthe transmitting transformer is tappedat its'mid-point,A or is divided into' two equal coils,vto permit theconnection, at'tlcemid-point, ofthe phantom circuit conductor 39m/nichyleads to the phantomfcircuit terminal apparatus 'at C, Ato be describedhereinafter.v f I 'In addition tothe fourequ'al primaries 34, 34, 35, 35the receiving transformer comprises' two which is connected tothelaments of apair` of thyrat'ron tubes 41, `4.2.j The lamentsare' vfedinl parallel from ja A.common source 443 and grounded. This sourcecfiilament heating pcvver may be directrcurrent as shown, or alternatingcurrent. The secondaries 49, 40 A ofthe receiving transformers areconnected attheir free terminals to the grids of 4tlle'tliyratron tubes4 1, 42,. Vstabilizing,battery (#17 of serted in thefgrid filamentcircuits of the thyra trons; l The plate. circuits of the thyratrontubes vin clude vtne coils 44 and 45 of a receiving polar relay and ,thecommonjcurrent source 46, the other terminal of Wliioliis grounded inorder to complete a circuit to the grounded filaments. The circuits ofthe thyratron tubes 4l and `42 areso arranged, as by means oftheimpedancenet- Work indicated generally ate?, that Whentube 4l-isr"operative and thereafter tube 42 starts, tube 4lbecomesncn-conductive, andi/ice versa. This action is explainedingreater detailin the description of the operation 'ofi tlfie system,here-v inafter. As already stated, the4 opposite end of line section -30isfbala'nced forv duplex operation by prises a receiving transformerFig. 1b) may be 'inf laf'lean's-ofy a balancing artificalline 33f`and" aree ceiving` transformer `50 1 having "four equal' .pri-1 maries andtwo-'equal jseconda'ries. v.1 -These prie maries and secondariesarearranged similarly tothe primaries 34,- 351and secondarie's 40.'of vthe`receiving s transformer at: terminal A.. .already 'dee' ,scribedl' Thesecondary v'51H ofA aL .transmitting transformer which.v forms Apart. of1 the repeating apparatus, is connected .to y the "junctions of.'.v theI line andv articial linei-coilspi receiving trans'-V fst;

former50;l The secondaries 'of receiving trans' g.

former' V5i)V are 4connected in the 'grid' circuits 'of thyratron tubes"52,-' 53. The plate circuits fof tubes '52, 53 includes coils 54 and5.5'which corre;-`

spondgenerally to coils 44 and45,y ofQtub-esf 41 and 42. i However, thecoils 54 and 55'formfp'art f thefrepea'tns Vapparatus and` feed. mathe"second line section' 31,` instead of actuating fthe'y armature of areceiving polar relay. as 'idoV .the 1 coils-44 and/45. A The platecircuits of the-thyratrons 52; 53 1nclude;v in addition to thecoilsvf54, 55, a common source of current 56 vand anetwork foryrendering onethyratron non condu'ctive when the otheris started and viceversac* This'lnetworkimayfbe similar to' network 41ans 42." f' v -1- Thecoils 54 andl55 form tl'ieprimariesof are--v peater transmitting I-transformer, 'the' secondary 5'7 of-which isconnected-to;the'junctions-of .the

line andf-articial'lin'e coils Yof a-receiving trans-l former 53connected to-line section '31;4 The secondaries of the receivingtransformer 58 are conofi-another pair of nected inithe gridcirc'uits'thyratron tubes 60,61 formin'gpart of vthe lre` peating apparatus.- Thep latefcircuits-'jeff thyratrons 60, `61 are' `fed from the source'56fandf.in

secondary 51 already referred-to? Y' 1 The .secondaries A51 `and 57 ofrthe frepe'ater s 4'lfassociated Witnzi-,hyratmns v noy clude coils 62and 631' which frm'prmaris of the repe'atertransmittingtransformer-having c transmitting transformers are both centrally icircuit 'conductors 64 andV4 respectivlmfwhicli lead to the phantomcircuit repeaterapp'arats to be describedhereinafter:

The' distant end ofline section ,'31 at terminal A comprises apparatussimilar to thatat terminal A connected tOlinesection 30. Thati's`,`itcom' 64=a`ssociated with .tapped to permitconnection-'theretooffphantoi A i abalancingjy artificial line' toprovide dlmlexfopiv eration over yline section 31.

` The secondaries of the receiving transformerii are connected'in-the Lgridcircuitsiof a pair' ofi-thyratros 66,' 66"] "The 1 plate circuits ofthe'thyratrons includezcoils'l "67 nec'tecl the terminalsof-thesecondary-'695of af... transmitting transformer having vits primary? -70-r connected* to 'the-f transmitter 71 atfterminal A The secondary 69of-'the transmittingtransformer at'terminalAoi: line section 3l istapped at its `mid-point for connection vtoa pnantombi cuit conductor/80i which leads tophantomcircit terminal apparatusat'th'e second 'Cl'terminalif The sidecircuit B,-.'Bicomprisesa` p air of' lin'e sectionsr72, 73.4 AEachy ofthe line sections -is'bal ancedat each' endbyartificialv lines lfor permit:V

ting duplex operation over-the lines'ections.: i vThe twoflin'e sectionsare jo'inedby 'repeating' apparatus similar -to that 'joining' thel*line sections Scand 31 of-side' circuit AArEach B terminara' providedwith 45a 'transmitter 74 di agrammatically representedY asfcmprising-Jzij-*generatori having one terminal grounded' and theother terminalarranged for connection to either of two vcoils 75 and 76,- the commonpoint of-Which is grounded. 'I'hejcoils 75, 76 form alternateprimariesof a transmitting transformer, the secondary 77 of which-isconnectedtojthe neutral points of the receivingv relay 78. Thereceivingrelay isrepresented diagrammatically as e formers at the near andcomprisingjfourgcoils, two vconnectedto Aline and tv/oto the balancingartificial line. :The secondaries 77 of the transmitting transdistantV Bterminals are tapped attheir mid-points by Vconductors 79 and8OVrespectively for connection to the phantom circuit terminal apparatusat terminals' C. v:'Briefly, the repeating apparatus for side circuitBBcomprises two pairs of thyratrons 81, 82 and 83, 84. One pairr isdesigned fortransmitting .from linesection 72 -toiline section 73, andthe other pairffor transmitting from line section 73 to line section 72.pair-81 and 8 2 are connected tothe secondaries of the repeaterreceiving transformer 85 in line section .72 and theplate circuits ofthe pair 81 and 82 are connectedjto the primaries ofV repeatertransmitting transformer 86 for line section73. Similarly, the gridcircuits of the pair 83, 84 are connected tothe secondaries oftherepreater receiving transformer 87 in line section 73, Yand theirplate circuits to the `primariesof the repeater transmitting transformer88 for linesection 72.

YThe mid-points of theV secondaries of repeater transmittingtransformers 88 and 86 are connected respectively to'phantomcircuitconductors 89 and 90. These phantom circuit conductors lead tothephantomlcircuit repeater apparatus.

f The phantom circuit CCVeXtends from'the near terminal Clbyway ofconductors 39 and 79 to the ,mid-points'fof the A terminal transmittingtransformer secondaries; thence over the line conductors in parallel andthe line conductors 72 Y in parallel tothe mid-points of the secondariesmitter 91, vsimilar ofthe repeatertransmitting transformers, and bywayof conductors `64 and 89 to the phantomvcircuitY repeatefrapparatus.l

The output of the phantom circuitrepeater apparatus extends by `way ofconductorsY and 90 tothe mid-points ofthe secondaries of the repeater 1transmitting transformers for vline sections 3l and u73 respectively,

ductors of the respective line sections in parallel Yto the mid-pointsof the transmittingtransformer secondaries at the'distantAand Bterminals, and by way of conductors and 80 tomA circuit apparatus at thedistant C terminal.

4As illustrated, the phantom circuit terminal apparatus at each terminalC comprises a transtom transmitting transformer 92. The phantomcircuitis balanced for duplex operation byV an I 9 2-*being connected93, the secondary oftransformer to the neutral pointsof a phantomreceiving transformer 94. The secondartificiali line ary ofreceivingtransformer94 is connecte-dito coupling transformer V and asource 97 of plate current, The two secondaries 98 and 99 of thecoupling transformerA are connectedy in the grid circuits of a pairzofthyratronsv 100, 101; Ther plate ,circuits of the thyratrons include thecom Vthe. free terminal of The 'grid circuits of the 4thence, over thecony n to that. shown at side circuit terminals The'transmitter 91isarranged to i supply positive and negative current to a phanand theusual 'network 103 one thyratron to stop when 4Across the terminals ofthe mon generator 102 designed to cause the other starts.

network 103 is connected a eldwinding 1040i a generator vhaving itsarmature 105 connected to the phantom local receivingvcircuitfortoanother linel section. Suitable adjustable shapingl' apparatus 106isassociated' with the field 104 of the generator so that the wave forminduced in shape. Y The apparatus shown at the distant terminal Cduplicates that already described.

The phantom circuit repeatingapparatus is connected between conductors64, 89 and conductors 65, 90 and comprises Vtwo' pairs of thyratrons107,108 and 109, 110. The sections of the phantom circuit at'therepeater are lbalancedr byr artificial lines 111 and 1l2. Thyratrons107'andv108 are controlled by phantom repeater receiving transformer 113and feed into the phantom repeater transmitting transformer 114,thenceover conductors 65 and 90. Similarly, thyratrons 109,

which repeatin the `opposite direction, are

controlled by phantom repeater receiving transformer115 and feed intophantom repeater trans'- the armature 105 may be adjusted to be ofproper mitting transformer 116', thencev over conductors 64 and 89. y.,

The operation of the duplexed and superposed system of Figs. 3a, 3b andSeis as follow's: t The wave form yof the signal in the primaryof the;sending transformer of either side circuit or of the phantom circuit isassumed to be substantially yscalare-top, as shown in Fig. 2a. Thissignal wave may, as already stated, be produced by a fork, a relay, acommutator, a ymultiplex distrbu'tonorthe like, the diagrammatic showingof the transmitter at 38, 7l, 74 and 91 being intended to represent anytransmitter capable of producing a signal wave of the desired type.

Assuming that` a signal is beingY transmitted overk the side circuit AAfrom transmitter 38 and that the signal Wave in primary 37 has the formshown in Fig. 2a: The wave is attenuated slightly onv the frontdue tothe inductance of the primary but is essentially square-top in shapeVtherey are intervals of no current in the secondary 36 whenever theprimary current is steady`r By s reference to Fig. 2b it will beseenthat a sharp peak occurs at the start of each signal, or, speakingaccurately, at the Yend of one signal and start of another. 1 l

' If the inductance of.. the primary iskept low enough so that thelpri'mary current reaches its steady state value beforereversal occursfor the shortest telegraph signal, then for all signal frequenciestransmitted to the primary up to that determined byv the time constantyof the primary,

the secondary impulses will ,be alike-regardless' of the frequency ofthe telegraph signals.

The sharp peaksof current of Fig. 2b are transmitted, over theV line'section 30 fof side circuit AA without aifecting the receiving apparatusconnected tothyratrons 41, 42v since this latteris arrangedin conjugateor non-interfering relation with respect to the transmitter 38. YBecausethe current peaks arealike for all signals, the short and long telegraphsignals are 'attenuated equally by the line- 30 and characteristicdistortion yis iso u 1,936,947. substantially eliminated. The same istrue Vfor,`

transmission over the other'vline sections.

The signal peaks of Fig; zbincoming from une 30 at the receivingtransformerv are applied to the grids of the thyratrons y52 and 53.-These peaks, alternately of positive and negative po.- larity, areapplied to the grids or" the thyratrons in such a direction as to makethe tubes tend to vstart alternately.4 If an incoming impulse starts thethyratron tube 52 current owsinits plate circuit and continues to flowtherein until Vthe next incomingimpulse starts rthe other thyratron 53.When ythyratron 53 starts, the plate Voltage on thyratron 52 is reducedand the latter is rendered non-conductive.y Similarly, when'the nextsucceeding incoming impulse starts the noninoperative tube 52, the platevoltage on thyra- 1 tron 53 is in turn reduced by the operationof thenetwork 59 in the plate circuits of thyratronsv 52 and 53, and thyratron53 'is in turn renderedinoperative.

Thus the series of sharp current pulses in line 30 produce alternatestarting pulsesin the grid circuits of thyratrons 52 and'53, and cause'the production of square-top half Waves inthe coils 54 and 55 of therepeater transmitting `transformer. If the square-top half-Waves wereproperly combined they would produce a wave form like that shown in Fig.2d. The alternate squaretop pulses in coils 54 and 55 by transformeraction produce in the secondary 57 of the repeater transmittingtransformer another identical series of sharp current peaks, like that`shown in Fig. 2b. This series is transmitted over line section 31 ofside circuit AA Without affecting the other channel of the repeater',lthat is, the channel in.- cluding thyratrons 66, 61. The receivingtransformer 64 at the distant terminal A applies the series ofimpulsesto the grid vcircuits of `receiving'thyratron's 66, 66 to causealternate operation of the latter. In the plate circuits of thyrae trons66, 66' is produced a combined Wave form like that shown inrFig.. 2dwhich causes operation of the armature of the receivingpol'ar relay` 68,69 to reproduce the original signa'lsu.

The voperation of the side circuit AA" fora signal sent from transmitter71 is the same'as for a signal sent from transmitter 38.` That' is,

the distributor or other transmitter '71 sendsto` the primary '70 aWaveform likethat shown in Fig. 2e. By transformer action4 there isproduced in the secondary 69 a series of peaks of current like thoseshown in Fig. 2".Which are transmitted over section 31 of sidefcircuitAA. At the repeater, thyratrons 60,161 produce square-top impulses intheir plate circuits which, in turn, pro- 4'duce a second series ofcurrent peaks like those in Fig. 2b. The second series istransmitted'over section 30 of side circuit AA and converted'by thecombinedy action of thyratrons 41, 42intoa' Wave form like that shown inFig. 2d. f f:

The voperation o1" the side circuit BB visino't greatly diierent :fromthat ko'f side circuit AA.

yreceiving transformer the received current peaks apply startingvoltages to the grids of thyratrons 81, 82 andthe latter are operatedalternately to produce square-top impulses of opposite signs in theprimaries of the repeater transmitting transformer 86. From thesecondondary of. transformer 88 into a secondseriespf Von f the lineinductionof sufiicient value to. .overla ware-formQike thatof Fia. 2t;'.By tlrlsflmer' 4action ,the square-top vWaves yare.converted:into Aa1.1d.173,1fand by Wayof conductors 30 and; 80 to fthephalntom receivingtransformer93 at the disary transformer 186 a second seriesiof.. currentpeaks like .those in' Fig. :2b `are transmitted .over the `linesectiony73 tothe coils o'f the. receiving' polar relay78.- In the.vlocal circuitfof the polar relay 78 diagrammatically indicatedbythearmae tureand contacts' ofthe relay,;a"wave Aform is producedv`which' corresponds to-tha't `shovvnfin i Fig. 20C' if? .11. "9'.

Similarly `a signal v.sent vfrom Vtransmitterfg1'74; of; side circuitYBB havingy the form shown iin Fig. 22, is transformed inthe; secondary'77 "of,i the. trans-1- mitting-transformer into a series'foi"currentpeaks of, the-form-shown in FigtZlL-sfor.transmission Yoversection v'73 yof side'circuit'BB'. the'iree' peater these currentpeaksljarej converted-ahy; thyratrons 83, 84 into square-top currentim-`Y pulses awhich whenl combined Wouldproduce a Waveiornrlike thatshownin Fig.2d.- The squareftop impulses rarein turnyconverted in vtheseca current peaks similar tovFig 2l. Thesearesent over.line-sectionv7:2 of `sidecircuit BB and fr eceived in thejcoilsgof the'receiving polar relay 17.8.

The Wave form ofiA the contacts tif-receiving relay 2.8 hasj the `formof Fig. 20.

'*t has .already been pointed'outfthat anordinary polar relay can beused ina system according to this inventiononly vin case there'isfnotpresent come the residual magnetism of y'the 'polar relay. if forexample one Aof the :conductorsxg'mjwere replaced by aground return,01.if an unbalance existed, in the metallic circuit T72, `there mightbesufficient induction in the: lineY .to overcome the residualmagnetismof' the 'relayfso thattherelay 1-10 u' :night fail to holdarmatureon aggiyenc'ontact j untilv the (next signal impulse Weiereceived.-; 'Io overcomeY this asimple locking circuit may. be restoredto. :This lis nO'tQilluStrated;speciiically vbutthediagrammatic:representationat 78 is in- 1.15r 'l tended vtorepresenta receiving relay; with `or Withoutl such a locking circuitggaslcircumstancesmay requira.. U .The operation of the phantom circuitbetween terminalsCC is lasfollovvsThetransmitter91 1-20 l at .theV`near, terminal causes fthe `.-1'loi v-in ithe primaryof transformer 92-of' gna having thevlave forinshown `in Fig. -2 11.15 the; secondaryakwave form likeg that of-Fig, 2 1-is produced, andistransmitted-over@onductors-3 9and 125 79, and the' phantomedllinesections-@fand 7 2 toV the vphantom circuity repeaterby Wayvofcouduc'tors y64 and 39. lIIere ;thesharp 'peaksof V current :areappliedfto .the gridsv o'tjthyratrons 110'! andy 108 as startingimpulses, causingalternate operation of the-thyratrons andtheproducfltion "in the plate circuit of I the thyratron tubes, `by" Wa'yfoftheprimaries of transformer. 114; .of

a Wave in the secondarygo'-.transformer ll 4. hav- .ing a` Wave formlikethatof Fig. 2b; This,. last nientiQnedWav-e is transmittedbywayofconducf tors 65 and 90 to the phantomedlinelsections31" tantterminal The impulses thus received are amplifiediir the three elementamplifierv tube $5 randfthe-amplied .current is passed; throughprimair-y 96; of a couplingftransormerI having secondaries 98 and `99-connected inthe gridl circuits of thyratrons 100 and 101. In theplate, circuit of the thyratronsthereis produced aV square-top wave formlike thatshown in Fig. 2d which supplies the eld 104 of a generator, they1 50 equivalent means.

of receiving transformer 115.

latter havingl its armaturev1`05 connected in a.V local circuit or toanother line section. If. necessary, the' wavef'in the plate circuitofthe thyratrons is suitably shapedy by the network 106 or thenfextendsthrough transformer 116,`conducltors 64 and 89, phantomed line sections30 and '12, and conductors 39 and '79 to the receiving transformer 94,amplifier 95, thyratrons i100 and 101 to the generator 104, 105 Vand'itsassociated apparatus. Y I

It will be obvious that the transmissions in two directions oversidecircuit AA do not interfere witheach other nor with the phantomcircuit transmissions nor with the transmissions inside circuit BB.lSimilarly, the4 transmissions in opposite directions over side circuitBB do not interfere with each other or with the transmissions overcircuits AA and CC. The transmissions i`nopposite directions overY thephantom Vcircuit' CC do not interfere with each other or with thetransmissionsv over the side circuits AA and BB. For this condition ofnon-interference toexist, however, thefvariouscircuits and thecorresponding` pieces ofapparatus therein must be duplicatesof oneanother or carefully` balanced against l one another. symmetricallyplaced coils of theV various transformers must be balanced. Itisbelieved unnecessary to point out specifically all the pairs of elementswhich must be balanced, as this is a matter which will be obvious to oneskilled in the art, in the light of the disclosure of the principles ofthis Vinvention. Y

Although themethod and means of this invention have been described inconnection with a" preferred embodiment thereof, it is obviousthat theinvention4 is not limited tother particular systems disclosed but iscapable of considerable modification without departure from the spiritof theV invention.r

We` claim: f y 1. A system ofV impulse telegraphy comprising means fortransmitting a square-top'wave, a line,

a transformer having its primary connected to said transmitting meansand its secondary to line,

ywherebyV said transformer produces from said square-top wave a seriesof sharply peaked lcurrentv impulses, one at'the start of eachsquare-top impulse, a receiver connected to line and means in saidreceiver Vfor converting said series of peakedimpulses into a square-topwave corresponding to said original transmitted'wav'e.

2.` A system of impulse telegraphy 'comprising means for transmitting asquare-top wave, a line, a transformer having its lprimary connected tosaid transmitting means andits secondary connected to line whereby aseries of non-continuous sharply peaked impulses oflalternate polarityare transmitted Vto said line, a receiver comprising a 'pair ofthyratron tubes oppositely connected to line and arranged to producefrom'said non-continuous peaked impulses afsquare-top wave substantiallycontinuous in form.

f 3'. A system of impulse telegraphy comprising means for transmitting asquare-top wave, Va line, aY transformer havingits primary connected tosaid transmitting meansand .its secondary connected to line, wherebya'series ofnon-continuous sharply peakedv impulses ofl alternatepolarity are transmitted to said line, a receiver connected to linecomprising means kfor amplifying vsaid peaked impulses, a pair ofthyratron-'tubes arranged to convert said amplified peaked currentimpulsesinto a 'square-top continuous'wave, a generator comprising afield winding. connected to said thyratron tubes to receive saidsquaretop continuous wave, and a signalreceiving cir-'- cuit connectedto the armature of saidgenerator.

4. The method of communicating overaftelegraphic circuit which comprisesproducing a square-top signal wave, transforming said wave byv inductiveaction into a second wave comprisinga series of sharplypeaked currentimpulses having one'peaked' impulse at `the start of each square-topimpulse of said square-top signal wave, transmitting said series ofvpeaked impulses, receiving said series .ofA peaked impulses,and-converting said series` ofv peaked impulses into` a square-,top wavecorresponding to said original signal wave.

5. Themethodof communicating overa telegraphic circuit which kcomprisesproducing a square-top signal wave' substantially continuous in form,transforming said -wave by inductive Aaction into a second wavecomprising aseries of non-continuous sharply peaked current impulseshaving one peaked impulse at the start of leach square-top impulse ofsaid square-top signal'wave, amplifying said series of non-continuouspeaked current impulses by kconverting it intoV a squaretop wave ofincreased energy content, retransforming by'inductive action saidamplified wave into Vak second` seriesof peaked currentimpulsestransmitting said last named impulses, Vreceiving saidretra'nsrnittedseries of peaked impulses and converting it into a square-top wavekcorresponding to saidro'riginal square-top signal wave.r

GpA-system for converting a non-continuous v circuits therefor, vsaidinput circuits comprising,

means for applying peaked non-continuous current impulses to saidthyratron tubes as starting voltages therefor, said output circuitscon'iprising` means for causing the starting of either tube to stop `theother tube, whereby the peaked impulses cause the production in thecombined'output circuit of `the thyratron tubes of contiguous square;-top impulses to produce a wave continuous in character. l I

" 7.In a system of impulse telegraphy as set forth in claim 1, theprimary of said transformer having a vlowv inductance such that theprimary current reaches al substantially steady state before reversaloccurs for the shortest signal impulse, whereby all signals areattenuated equally over. the line and distortion is eliminated. l

RONALD v. Monofnnsfrrzmv.s` vJOHN n. rmcKENBERG.

DISCLAIMER 1,-936,947.-Ronald V. Morgenstern, Irvington, and John H.Haelcenberg, Jackson Heights7 N. Y. TELEGRAPH SYSTEM. Patent datedNovember 28, 1933. Disclaimer ied September 16, 1942, by the assignee,The Western Union Telegraph Company'. Hereby enters this disclaimer t0claim 6 of said patent.

[Oficial Gazette 0ct0ber 13, 1942.]

